The inventive subject matter comprises stiffening framed structures while improving their thermal insulation by rearranging polyurethane foam insulating material. Despite polyurethane foam's low modulus of elasticity, it has been found that partially embedding a frame in an adhesive foam can substantially increases the stiffness and load carrying capacity of framed structures while eliminating thermal bridges and reducing the number of frame members.
There has been a need to strengthen buildings by increasing a framed structure's load capacity at little or no cost for all types of applications. Stronger framed structures result in the ability to carry greater loads and/or increase spacing between frame members which reduces cost. To date, increasing load capacity of frame members and their supported panels has been accomplished by changing the frame member's or panel's design to use materials with an increased modulus of elasticity and/or with an increased moment of inertia and/or by shortening the frame member's span.
There has also been a need to use materials more efficiently in that typical building walls, for example, are comprised of several layers of different materials with each providing a different function to overcome the deficiencies of other materials. This is a waste of materials and labor and there is a need to consolidate wall functions into fewer, more versatile materials that will improve quality, speed construction and save costs. One such material that can do this is self-adhering polyurethane foam.
Spray or poured polyurethane foam has been used in building construction for the past 70 years primarily as an expensive thermal insulating material and many of it's other desirable properties have been overlooked. One unique property is polyurethane foam's ability to be applied as a liquid in ambient temperature and proceed to expand and adhesively bond to anything it comes in contact with during it's expansion. This property enables insulated building panels, for example, to be manufactured by simply positioning a cladding, face down, with a frame about one inch above and then applying the liquid polyurethane foam to the cladding's backside. The foam expands and self-adheres to the cladding and frame resulting in a composite framed structure complete with continuous and cavity insulation, no thermal bridges (nails) and an air, vapor and moisture barrier—all with minimum labor.
Composite action has been widely applied to wall, floor or roof assemblies where increased load capacity and greater structural integrity has been achieved by adequately bonding a sheathing to the frame members. It is also well known that polyurethane foam can be used to bond sheathing or claddings to frame members and thereby reduce racking and increase the structural integrity of an entire structural wall or roof section. However, no prior art has recognized that embedding frame members in self-adhering polyurethane foam can result in substantially increasing a framed structure's lateral/transverse load bearing capacity.
U.S. Pat. No. 3,258,889 (Richard A. Butcher) discloses a structural wall comprised of polyurethane foam bonded to an interior wallboard and to the sides of studs and teaches added stiffness of the framed wall to enable thinner panels and lighter frame members. U.S. Pat. No. 3,641,724 (James Palmer) discloses a wall section comprised of an exterior cover bonded to the sides of stud members by a polyurethane foam that increases the strength of the entire structure. U.S. Pat. No. 4,471,591 (Walter E. Jamison) discloses a wall assembly with an exterior section comprised of polyurethane foam bonded to sheathing and to the sides of studs. U.S. Pat. Nos. 4,748,781 & 4,914,883 (Stanley E. Wencley) discloses polyurethane fillets bonding a panel to frame members to provide an increased strength bonded structure.
U.S. Pat. No. 5,736,221 (James S. Hardigg, et al) discloses two half panels with each having a face and a web molded to the face's backside and the webs bonded together to provide a panel having bending strength in all directions. U.S. Pat. No. 6,099,768 (Michael R. Strickland et al) discloses a frame reinforced with wire mesh and embedded in polyurethane foam that bonds a backer board to the frame. U.S. Pat. No. 8,397,465 (Jeffrey M. Hansbro et al) discloses a wall assembly comprised of polyurethane foam panels bonded to the sides of structural members (studs) and to foam boards continuous over the structural member's edge. U.S. Pat. No. 8,696,966 (Jason Smith) discloses a method of fabricating a wall structure whereby polyurethane foam is applied against a form and the foam expands to become a panel bonded to the edges and sides of support members (studs) within a wall frame. US 2012/0011792 (Dean P. DeWildt et al) discloses a light-framed wall structure comprised of sheathing attached to studs with a top and bottom plate and spray polyurethane foam in the cavity. The wall structure has high axial point, lateral and transverse load bearing properties. WO/2013/052997 (John Damien Digney) discloses a composite panel system reinforced with wire mesh and comprised of a structural cladding spaced apart from and bonded to a studded frame with polyurethane foam that is between and continuous over the studs.
US 2014/0053486 (Anthony Grisolia et al) discloses a wall structure including support members inside the frame (studs) and a polyurethane foam panel both continuous over and between the support members. US 2014/0115988, US 2014/0115989 and US 2014/0115991 (Michael J. Sievers, et al) discloses a wall assembly of a frame assembly with vertical members (studs) and an insulating foam layer disposed between and on top of the vertical members. US 2014/0174011 (Jason Smith) discloses a method of fabricating a wall structure comprised of bonding polyurethane foam to the edge and sides of frame members. US 2015/0093535 (James Lambach et al) discloses a framed panel with a polyiso board continuous over frame members and bonded to the sides of frame members with polyurethane foam. US 2015/0376898 and US 2017/0044759 (Kenneth R. Kreizinger) discloses a frame supported panel having increased load capacity derived from polyurethane foam bonded to a cladding and to frame members.
The problems to be solved by this inventive subject matter are: first, to increase the load carrying capacity of composite framed structures at little or no additional cost. Second, to manufacture stronger structures more efficiently, and third, to increase the thermal insulating value of composite framed structures by eliminating thermal bridges and reducing the number of frame members.